hunger, diet, and global warming

1
hunger, diet, and global warming
Gidon Eshel Dept. of the Geophysical Sciences Un
iv. of Chicago Chicago, IL 60637 Tel (773) 702-
0440 Email geshel_at_uchicago.edu Web http//geos
ci.uchicago.edu/gidon
Santa Fe, June 2006
2
Chapter 1 food shortage, or food excess?!
3
World Population is
about 6.4 billion people At 2100 kcal a day,
this means we need about 4.9 x 1015 kcal/year g
lobally.

4
mean, 1997 2.7 T/hectare or 0.27 kg/m2
Source Food and Agriculture Organization of the
United Nations , FAOSTAT Statistical Database (F
AO, Rome, 1997)
5
at roughly 4 kcal per gr, to feed everybody we
need

or 4.5 x 106 km2 every year. Allowing for an
efficiency of 50, we get about 107 km2 per year.
Since the Earths arable land surface
area is about1,2,31.4 x 107 km2, we have more
than enough land to feed everybody, with plenty
to spare! 1 http//www.rockford-india.com/ir
rigation-arableland.htm 2 http//www.cnie.org/po
p/conserving/landuse.htm 3 it in fact rises, at
about 3 x 105 km2 (2.6 Pennsylvanias) per decade!!
6
are people hungry?
in absolute numbers, sadly, they are
7
are people hungry?
but as a fraction of the total
the rates are declining
Source The UN Food and Agriculture Organizati
on,
FAO 1998
8
The UNs FAO also states that
... As a world average, food availability for
direct human consumption (on a per-person basis)
grew 19 percent to 2720 Kcal/day between 1960 a
nd 1994/96.
FAO Symposium on Agriculture, Trade and Food
Security Issues and Options in the Forthcoming
WTO Negotiations from the Perspective of Develop
ing Countries, Geneva, 23-24 September 1999, Pap
er 1 Salient trends in world agricultural
production, demand, trade and food security
9
meanwhile, as worldwide hunger rates drop,
a new, perhaps just as devastating, and most
likely
harder to fix, problem rapidly arise...
age
From Physical Activity and Older Americans

Benefits and Strategies.
June 2002. Agency for Healthcare Research and
Quality and the Centers for Disease Control. htt
p//www.ahrq.gov/ppip/activity.htm
10
Historic rates of people with BMI30 kg m-2 in
various countries. (Source Kopelman, P. G., O
besity as a medical problem. Nature,
404, April 6 2000, pp. 635-643)
11
no data
10-14
15-19
20
US prevalence of BMI30 in 91, 95 and 2000.
Sources Mokdad, A. H., JAMA, 282(16), October
27, 1999, 1519-1522 Mokdad, A. H., JAMA, 286
(10), September 12, 2001, 1195-1200
12
Global
data. Sources Mokdad, A. H., JAMA, 282(16),
October 27, 1999, 1519-1522
Mokdad, A. H., JAMA, 286(10), September 12, 2001,
1195-1200
13
the problem with obesity 1
Source Centers for Disease Control and
Prevention. Promoting Active Lifestyles Among O
lder Adults. National Center for Chronic Disease
Prevention and Health Promotion.
Nutrition and Physical Activity.
14
the problem with obesity 2

2000, 3.5
Percentage of national health expenditures att
ributable to
obesity, by country.
Canada, 1999, 2.4
Australia, 1994, 2
France, 1995, 2
USA, 1998, 5.7
USA, 1986, 5.5
USA, 1999, 7
N. Zealand 1997, 2.5
Portugal
Source Thompson, D. and A. M. Wolf, 2001 The
medical-care cost burden of obesity. Obesity Rev
iews  2(3), 189-197.
15
the problem with obesity 3
... Obesity is associated with a 36 increase in
inpatient and outpatient spending and a 77
increase in medications, compared with a 21
increase in inpatient and outpatient spending and
a 28 increase in medications for current
smokers.
Source Strum, R., 2002 The effects of obesity,
smoking, and drinking on medical problems and co
sts. Health Affairs, 21(2),
245-253
16
and one more
from Thompson, D., et al., 2001 Body Mass
Index and Future Healthcare Costs A
Retrospective Cohort Study.

Obesity Res., 9, 210-218.
25,000
cumulative health-care costs
25BMI30
208
9
7
6
0
years of follow-up
17
so the picture is
schematically something like
2000
too much
proportion of the whole global population
too little
time
according to G. Gardner and B. Halwei, Worldwatch
paper 150 Overfed and Underfed, March 2000, the
crossover occurred in 2000, with 1.1 billion
apiece
18
Sadly, obesity does not necessarily mean
abundance!
... Malnutrition and obesity
coexist in the same
settings ...
Source Dr. Manuel Pena, the Pan American Health
rganization, "Obesity and Poverty A New Public
Health Challenge."
19
what causes the shift toward obesity?

• of the multitude of causes, I find particularly
  important
  
• the structure of agriculture
• defective distribution system

20
an important aside is that people dont move
enough
Source Cordain, L. et al., 1998 Physical
activity, energy expenditure and fitness An
evolutionary perspective. Int. J. Sports Med.,
19(5), 328-335.
21
the number of US farms drop
22
while production becomes more centralized
4-firm concentration ratio
From Heller and Keoleian, Life cycle-based
sustainability indicators for assessment of the
US food system. Univ. of Michigan Center for Sus
tainable Systems Report No. CSS00-04,
Dec. 6 2000
23
profit only 3.5!!
1997 data
Source USDA Food Review, 2000, 23(3), 27-30.
24
as a result, competition is fierce
25
and food manufacturers are desperate...
From Table 1, page 12, Nestle, M., Food
Politics, Univ. of California Press, 2002
Advertising expenses, 9 leading food
manufacturers
26
to convince people to buy their stuff

food manufacturers must process as heavily as
they possibly can,
so as to add value...
1998 data from Nestle, M., Food Politics,Univ.
of California Press
27
also, they make stuff sweet, salty and fatty
28
a huge issue is subsidies
Source Environmental Working Group Farm Databas
e Version 2.0 http//www.ewg.org/
29
54 animal feed
8 sweeteners
2003 data. Source National Corn Growers
Association, http//www.iowafarmer.com/corncam/co
rn.html

30
Source http//www.biotech-info.net/
part of the reasons Coke is so cheap
part of the reason burgers are so cheap
31
also, because subsidy promotes large farms

• subsidy received 95-02
• top 1 25 billion
• bottom 80
• 15 billion

corn subsidy concentration
Source Environmental Working Group Farm
Database
Version 2.0 http//www.ewg.org
32
farm lobby is so damn powerful...
33
So
A policy that will fight obesity is also one
consistent with fighting world hunger. Unfortunat
ely, such a policy will be roughly the inverse o
f the policies now in effect in the US.
As the New York Times (Editorial, April 13, 2004)
puts it ... Almost two-thirds of America's c
orporations paid no federal income taxes during
the late 1990's, when corporate profits were soa
ring. Nine out of 10 companies paid less than th
e equivalent of 5 percent of their total income
...
34
What can YOU do?!
Global Warming is about GHG emissions. All we
need is to simply change the way we do every last
thing, to completely rethink every bit of
societal infrastructure, and we should be all
right.
35
" The food production system accounts for 17 o
f all fossil fuel use in the US" in 2002
(Horrigan et al., Env. Health Perspectives, 110(
5), May 2002, 445-456 Pimentel and Pimentel
(Eds.), Food, Energy and Society, Univ. of
Colorado Press, 1996)
36
for comparison (using 1997 data)
i.e., food production represents a major
energy sink,comparable to the other major sectors
37
fine, so our collective diet has a significant
planetary footprint but how about an
individual?! Are some dietary choices the nutriti
onal equivalent of driving an SUV?
let's gather the calculation's building blocks,
and find out
38
using personal vehicles alone, your average
American adult drives 8,300 miles a year

• At 6337 highway/city driving
• Prius 8,300 / 57 mpg 146
  gal
  
• Camry 8,300 / 30 mpg 278 gal
• Suburban 8,300 / 14 mpg 595 gal
  
  
• At 1 US gallon gasoline 115,000 BTU
• (from the Oak Ridge National Lab Bioenergy
  Information Network, assuming the more
  appropriate LHV)
  
• Prius 1.7 x 107 BTU year-1 1.19
  ton CO2
  
• Camry 3.2 x 107 BTU year-1 2.24 ton CO2
  
  
• Suburban 6.8 x 107 BTU year-1 4.76 ton
  CO2
  
• In 2004, 24 tons of CO2-eq per capita annually
  (US)

39
Energy consumption Food
Heller and Keoleian, 1999, Report No. CSS00-04 of
the Center for Sustainable Systems, School of
Natural Resources and Environment, University of
Michigan, Ann Arbor, MI
40
Total 02 US edible calorie production 1.4x1015
BTU yr-1 (3774 Kcal/person/yr, while the necess
ary ingested is roughly 2100) FF consumption du
ring this production 10.2x1015 BTU yr-1
Overall efficiency 100(1.4/10.2)(2100/3774) 7
.6 To ingest 2100 Kcal day-1 , the average Ame
rican uses
4 x 107 BTU person-1 yr-1
Versus driving, 1.7x107 to 6.8 x 107 BTU person-1
yr-1
41
Comparative energy consumption

• Transportation and diet

42
so car (1.7 to 6.8) x 107 BTU person-1 year-1

food 4.0 /-?? x 107 BTU person-1 year-1
That is, nutritional choices can be just as imp
ortant to one's planetary footprint as the car
one drives, and there's a HUGE latitude in food
choices!!
43
Efficiency animal-based foods
100 x (total energy in output) / (fossil fuel
energy in input)
average 10-15 caloric efficiency
modified from David Pimentel Marcia Pimentel,
Food, Energy and Society, University Press of
Colorado, 1996, Tables 8.2, 9.4
44
Efficiency plant-based foods 100 x (energy in ou
tput) / (fossil fuel energy in input)
average 220 caloric efficiency
Don't worry about eating your spinach!
David Pimentel Marcia Pimentel, Food, Energy
and Society, University Press of Colorado, 1996,
pages 114-134
45
Energy efficiency of foods

• Edible energy/fossil fuel input

Calculated from Pimentel Pimentel, Food, Energy
and Society, University Press of Colorado, 1996
and Food Balance Sheets 2005 (FAO).
46
Let's compare competing diets
c 3774 Kcal / (person x day) X 365 days / yr X
1 BTU / 0.252 Kcal X 710-8 ton CO2 / BTU
0.385 ton CO2/(person X yr)
a fraction of dietary caloric intake from
animal sources e caloric efficiency of producin
g animal-based foods (average 0.14)
f caloric efficiency of producing plant-based
foods (average 1 to 4)
47
a 0.1
a 0.28
a 0.4
48
beyond this general point
to make progress, we must consider specific diets
that have specific mean e and f
Derived from the below equation by setting a 0
49
defining semi-realistic diets
eggs, dairy, meats, veggies
observed facts our
devised diets
50
1.2, 2, 4
51
But - this takes note of CO2 alone, while food
production also produces other GHGs
For completeness, we must also consider
Methane
Nitrous Oxide
52
Estimated total GHG emissions associated with
food production
CO2-eq yr-1 person-1
Methane and N2O based on 1994 EPA emissions data
2.45
0.94
0.38
0.20
0.02
4 tons of CO2-eq per person per year!
53
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54
Let's (generously) assume a 15 animal product
efficiency, and a run-of-the-mill 50 of calories
from animal products
such a diet requires 1.96 x 107 BTU a year
by contrast, this person's vegan counterpart
requires 0.25 x 107 BTU a year
the difference, 1.7 x 107 BTU person-1 year-1,
is similar to the your entire annual driving if y
ou own a Prius!!!
55
The added benefit is, of course, health
of US GDP spent on health care 1960 5.1
1991 13.4 2002 14.9 2003 15.3
DOE/EIA, World Energy Use and Carbon Dioxide
Emissions, 1980-2001, May 2004
OECD countries Australia, Austria, Belgium
,Canada, Denmark, Finland, France, Germany,
Germany, Greece, Iceland, Ireland, Italy, Japan,
Luxembourg, Mexico, Netherlands, New Zealand,
Norway, Portugal, Spain, Sweden, Switzerland, Tu
rkey, UK, USA
56
and the health care sector is not particularly
efficient
Krackler, Schipper and Sezgen (1998), Energy
Policy, 26(15), 1137-1152
kwh m-2
weighted averages based on floor area in the
U.S., Japan, Canada, France, Denmark and Sweden
57
most are aware of the importance of total fat
58
and only slightly fewer are aware of the
importance of the
kind of fat ingested
American Journal of Clinical Nutrition, 78(3),
544S-551S, September 2003
P for trend 0.001
59
American Journal of Clinical Nutrition, 78 (3),
544S-551S, September 2003
mean/- 95 CIs
60
American Journal of Clinical Nutrition, 78 (3),
544S-551S, September 2003
61
American Journal of Clinical Nutrition, 78 (3),
544S-551S, September 2003
62
total fat intake and breast cancer
Int. J. Cancer, 15, 1975, 617-631
age-adjusted death rate per 105
animal fat intake, gr/day
animal fat intake and breast cancer
63
age-adjusted death rate per 105
vegetable fat intake, gr/day
but for plant fat intake vs. breast cancer - the
correlation collapses!
64
in California Seventh-day Adventists adjusted
for age, smoking, exercise, BMI, hypertension,
and food preferences.
American Journal of Clinical Nutrition, 70(3),
532S-538S, September 1999
men
95 CIs
Relative risk of definite fatal ischemic
heart disease
frequency of beef consumption
65
most attribute such results to animal fat intake.
While this is certainly important, animal protein
intake is probably as important to cancer
prevalence as animal fat is to CVDs.
activity of the enzyme responsible for turning
ingested aflatoxin into the DNA-altering
derivative
Mgbodile and Campbell, 1972 J. Nutr., 102, 53-60
66
enzyme activity, as expected, results in less
aflatoxin binding to three elements of cell nuclei
Preston et al., 1976 Life Sci., 19, 1191-1198
67
Appleton and Campbell, 1982 Nutr. Cancer, 3,
200-206
Dunaif and Campbell, 1987 J. Nat. Cancer Inst.,
78, 365-369

foci response
20
5
dietary protein level
foci response
high AF low protein
low AF high protein
68
adequate protein for body growth
Dunif and Campbell, 1987 J. Nutr. , 117,
1298-1302
Dunaif and Campbell, 1987 J. Nat. Cancer Inst.,
78, 365-369
foci development
20 Protein
foci development
5 Protein
dietary protein
69
Early foci, Lifetime
22
14
6
dietary casein
protein type
Schulsinger et al., 1989 J. Nat. Cancer Inst.,
81, 1241-1245 Youngman and Campbell, 1992 Carcin
ogenesis, 13, 1607-1613 Youngman, 1990 Ph.D. the
sis, Cornell Univ., Ithaca
70
these results hold for actual tumors
(as opposed to tumor precursors)
Tumor development at 100 weeks
Youngman and Campbell, 1992 Carcinogenesis, 13,
1607-1613 Youngman, 1990 Ph.D. thesis, Cornell U
niv., Ithaca
71
and another work
Cheng et al. (1997) Hepatology, 26, 1351-1354
72
other species, other carcinogen
Hu et al., 1997 Oncogen, 15, 2795-2801
73
another dimension of the problem is our export of
the "American Way", complete with what is
undoubtedly among the world's most awful diets
74
Popkin (1997), Public Health Nutrition, 1, 5-21
75
obesity rate of change patterns in the developing
world
Popkin (2003), Development Policy Review, 21,
581-597
percent
Mexico 88-89
Brazil 74-96
Morocco 85-99
Thailand 91-96
China 89-97
76
Food and Nutrition Bulletin, 22(4) (supplement)
2001, The U.N. University
percent overweight in rural India
women
men
77
Sanghavi et al. (2004), JAMA, 292, 2860-2867
adjusted BMI of foreign-born individuals
(N4,631) by years of residency in the U.S.
incidence of indicated BMI category
years of residence in the U.S.
78
So

• what you choose to eat has planetary effects as
  big as, say, what you choose to drive or where
  you choose to live
  
• eat less animal-based food